The present invention relates to drill bits for drilling in subterranean formations and, in particular to a method of making a diamond faced cutting element having a plow-shaped cutting surface.
Cutting elements having plow-shaped cutting surfaces are well known, as disclosed for example in U.S. Pat. Nos. 1,544,757 and 4,333,540, and in British Patent No. 449,974. Such cutting surfaces, which may have a diamond substance bonded thereto, perform a plowing action to promote the discharge of cuttings away from the cutting element. That cutting action is especially beneficial in relatively soft formations.
Techniques for bonding a diamond substance onto a flat surface of a substrate are well known. However, the bonding of diamond to mutually angled surfaces would involve considerable difficulties. In the afore-mentioned U.S. Pat. No. 4,333,540, it is proposed to bond the diamond to the V-shaped surface of a substrate. An alternative proposal disclosed in that patent involves the bonding together of two flat diamond composite drill blanks at a suitable angle. The former technique would be very difficult, while the latter technique, to the extent that it can be understood, would be expensive in that it requires the use of two commercially available flat diamond blanks to make a single cutting element.